Conrad Felixmüller. "Frau vor der Stadt". Junge Menschen, 3. Hamburg, 1925
“German Expressionism emerges as a movement of immense variety. Its stylistic intentions extend from the masters of Die Brücke through Beckmann and Kokoschka; that is, from the artists who first redefined theme, figure, and form to those who worked not from an inner striving after a new, 'as yet not existent' pattern, but established themselves as followers of fashion, some more gifted than others. We must remember in this connection that the so-called second wave of Expressionism had set in by c. 1919 with the emergence of Felixmüller, say -and that after 1919, when Expressionism was enjoying wide recognition, it was regarded as 'modern' to accept Expressionist principles of style.”
Lothar Lang. Expressionist book illustration in Germany, 1907-1927. London: Thames and Hudson, 1976 (p. 22)